VANCOUVER (miningweekly.com) – Junior explorer Broadway Gold Mining has started work on a 3 050 m Phase III surface-drilling programme targeting copper/gold porphyry mineralisation at the company’s 100%-owned Madison project, in the fabled Butte-Anaconda mining region of Montana.

Extensive geological interpretation of Phase I and II results, gathered earlier this year, has identified multiple priority target areas interpreted to be associated with a copper/gold porphyry system at depth and located within a well-mineralised, 3.2-km-long geological, geophysical and geochemical trend.

“The prospect of finding the porphyry mineralisation adds a fourth shot at building a mine,” noted president and CEO Duane Parnham in an interview with Mining Weekly Online.

"We are excited that our Phase III programme will include drilling into what we believe is a copper/gold porphyry system at depth. If we can prove that the porphyry target is consistent with our geological model, not only will the Madison project be a ‘company maker’, it adds a third dimension to the native copper skarn zone and massive sulphide potential from a mining perspective,” he said.

Parnham said that further drill targets at Madison include the underground massive sulphide zone, an extension of which is indicated immediately to the north of the 600 level by a recent Mise-a-la-Masse survey, the shallow skarn jasperoid copper zone and flanking shallow skarn gold zone.

Broadway is fully funded for completion of the Phase III programme, he noted.

The focus of the first three drill holes will be distinct induced polarisation (IP) and time-domain electromagnetic targets, including the NC, SE-1 and SE-2 chargeability highs.

Broadway will also target the strong Mise-a-la-Masse anomaly located north of the known zone of massive sulphide mineralisation on the 600 level of the Madison mine, where Broadway delivered underground drilling results including 24.5 g/t gold and 0.39% copper over 30.28 m in hole U17-05; and 41.65 g/t gold and 0.38% copper over 11 m, in hole U17-06.

Previously, surface drill hole C17-20 penetrated the edge of the Mise-a-la-Masse anomaly and returned a massive sulphide intercept of 1.247% copper and 1.84 g/t gold over 23.8 m.

The new drill programme will also look to extend the auriferous and cupriferous jasper mineralisation consisting of native copper and gold, trending to the northwest from the Madison mine.

Drilling highlights to date from this zone returned 2.57% copper and 0.15 g/t gold over 30.2 m in a longer interval of 1.725% copper and 0.097 g/t gold over 49.4 m in hole C17-16; and, 1.02% copper and 0.159 g/t gold over 31.1 m in hole C17-17.

The IP survey strongly suggests that a second anomalous zone with similar geophysical characteristics lies to the northwest of the anomalous zone hosting the auriferous and cupriferous jasperoid.

“There must be some juicy source somewhere on the property, and we can tell that it must be big and high grade to be able to produce the disseminated mineralisation we’ve encountered to date. If we hit a porphyry, one can expect a lot more drilling to ensue, because of the usual sheer size of porphyry deposits,” Parnham stated.

The company assumes that a porphyry system produced a generation of fluids, which formed the skarn zones discovered to date along faulted intrusive contacts currently exposed in accessible mine workings and at surface. The mineral characteristics of the skarn zones are consistent with a significant source of volatiles and sulphur and a possible copper/gold porphyry at depth, the company advised.

According to him, any of the known mineralised zones could probably, in time, become a standalone operation, especially since Madison is a past-producing mine, with permitted infrastructure in place to conduct trial mining of the massive sulphide ore deposit, should conditions warrant. However, Parnham said, the final mine plan will more likely entail a combination of the various options available.

He said that the company might consider making use of available capacity at Barrick Gold’s Golden Sunrise mine, to toll mill initial production. However, the company has a cyanide permit in hand, which today is difficult to secure, with increased pressure from environmentalists against it. However, increased deregulation under the Donald Trump administration could spell improved conditions for mine permitting in Montana going forward, he noted.

Broadway plans to periodically release drill results, once the core has been logged, sampled and complete analysis is received.